Orally active androgens

ABSTRACT

Novel, orally active androgens are 7α-substituted Δ 14 -nandrolone derivatives. The compounds satisfy the general formula:                    
     wherein 
     R 1  is O, (H,H), (H,OR), NOR, with R being hydrogen, (C 1-6 ) alkyl, or (C, 1-6 ) acyl; 
     R 2  is selected from the group consisting of (C 2-4 ) alkyl, (C 2-4 ) alkenyl, or (C 2-4 ) alkynyl, each optionally substituted by halogen; or 
     R 2  is cyclopropyl, or cyclopropenyl, each optionally substituted by (C 1-2 ) alkyl, or halogen; 
     R 3  is hydrogen, (C 1-2 ) alkyl, or ethenyl; 
     R 4  is (C 1-2 ) alkyl; 
     R 5  is hydrogen, or (C 1-15 ) acyl; 
     and the dotted lines indicate optional bonds.

This application is a divisional of U.S. application Ser. No.09/918,626, filed on Jul. 31, 2001 now U.S. Pat. No. 6,541,465, which isa divisional of U.S. application Ser. No. 09/613,350, filed on Jul. 11,2000 now U.S. Pat. No. 6,313,108.

The invention is in the field of orally active androgenic hormones, morespecifically Δ¹⁴ derivatives of 19-nortestosterone.

Testosterone derivatives are known. As a medicine testosterone itself,the natural male hormone, has many known drawbacks as far as methods ofadministration are concerned. It has a short-lasting activity, isinsoluble in the usual pharmaceutically acceptable media, and is notvery potent. The more potent dihydrotestosterone (5α-reduced form oftestosterone) is considered a health-risk, notably for the prostate.

A more potent androgen is 7α-methyl-19-nortestosterone (MENT) disclosedin FR 4,521 M and U.S. Pat. No. 5,342,834. An important drawback ofMENT, however, is its unfavourable kinetics which limits its use as anorally active androgen.

In the field of pharmaceutical preparations in general it is a commondesire for a medicinal agent to be orally active. Oral dosage forms,e.g. solid dosage forms such as tablets and capsules, are among the mostwidely accepted forms of administration. In the field of androgens, aparticular desire exists for the oral administration in connection witha utility such as male contraception. Since in the area of femalecontraception the word “pill” has almost become a synonym for reliablebirth-control, it is evident that also in the case of male contraceptionoral activity is desired, so as to enable providing a male “pill.”

An androgen having a special position in the field, is the so-called“Segaloff steroid” which is a 19-nortestosterone derivative having, asin MENT, a 7α-methyl group, and which has a double bond between carbonatoms 14 and 15 (Δ¹⁴). This special position is due to the fact that ithas long been recognized as the most potent oral androgen known. See,int.al. Avery et al, Steroids, 55, 59 (1990). The compound, togetherwith its 7α-H analogue, is also known from GB 1,341,601.

Despite having a special position in the field, the “Segaloff steroid”has not found practical use, which may be due to several drawbacks ithas for clinical utility. E.g., with 19-nortestosterones metabolicstability is an issue. Thus it is known from GB 1,341,601 that thesecompounds are prone to metabolic inactivation by hepatic17β-hydroxysteroid dehydrogenase. The classic solution to this problem,the introduction of an alkyl group in the 17α position is believed to beresponsible for unsatisfactory results such as a limited activity.

Several, mostly very old publications can be mentioned which form thefurther background-art relating to groups of steroid compounds whichinclude 19-nortestosterone derivatives. None of these references teachesorally active androgens.

Thus, in FR 1,432,561, published in 1966, 19-nortestosterones like MENThaving an alkyl substituent at C-7 are employed as a starting materialfor hormonal agents having a double bond between carbon atoms 5 and 6.Alkyl groups other than methyl are not disclosed.

BE 861 224 concerns all possible esters of a wide variety of17-hydroxysteroids. The disclosure, which dates from 1976, specificallyteaches that certain esters are desired for prolonged activity of thesteroids. Among the large group of steroids disclosed are oestrogens,anti-oestrogens, androgens and anabolics. A great many possiblesubstituents at various positions is given, among which are methyl andethyl at C-7.

Chemical Abstracts 110: 95601y (1989) refers to a 17-hydroxy acetate of7-allyl-19-nortestosterone as an intermediate in the synthesis of7-allyloestradiol.

EP 159 739 teaches immunomodulating agents of the oestrane series,including particularly Δ⁴- and Δ⁵⁽¹⁰⁾-oestrene derivatives having analkyl substituent in position 6 or 7. Said alkyl substituent typicallyis methyl.

DE 20 43 404 concerns 7β-steroids which have anti-hormonal activities.The alkyl substituent mostly is methyl, but ethyl and propyl aredisclosed as well. In the synthesis of 7β-ethyl-19-nortestosterone,which is a compound according to the teaching of DE 20 43 404, the7α-isomer is formed as well. It is not taught to use this isomer foranything, and the teaching of this document does not distinguish theethyl or propyl substituents from the methyl moiety.

As background art reference is further made to Solo et al, Steroids, 40,603-614 (1990). Disclosed herein are various 7α-alkyl derivatives oftestosterone.

It is an object of the invention to provide orally active androgenswhich are an improvement as compared to the Segaloff steroid in thatthey are better suitable for clinical use, and particularly possesssufficient oral activity and metabolic stability.

According to the invention, compounds are provided satisfying thegeneral formula I given below.

wherein

R₁ is O, (H,H), (H,OR), NOR, with R being hydrogen, (C₁₋₆) alkyl, or(C₁₋₆) acyl;

R₂ is selected from the group consisting of (C₂₋₄) alkyl, (C₂₋₄)alkenyl, or (C₂₋₄) alkynyl, each optionally substituted by halogen; or

R₂ is cyclopropyl, or cyclopropenyl, each optionally substituted by(C₁₋₂) alkyl, or halogen;

R₃ is hydrogen, (C₁₋₂) alkyl, or ethenyl;

R₄ is (C₁₋₂) alkyl;

R₅ is hydrogen, or (C₁₋₁₅) acyl;

and the dotted lines indicate optional bonds.

The invention includes pharmaceutically acceptable salts or esters,prodrugs and precursors of the above steroids.

The term (C₁₋₆) alkyl as used in the definition of formula I means abranched or unbranched alkyl group having 1-6 carbon atoms, like methyl,ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, andhexyl. Likewise, the term (C₂₋₄) alkyl means a branched or unbranchedalkyl group having 2-4 carbon atoms and the term (C₁₋₂) alkyl means analkyl group having 1-2 carbon atoms.

The term (C₂₋₄) alkenyl means a branched or unbranched alkenyl grouphaving at least one double bond and 2-4 carbon atoms. Preferred alkenylgroups have 2-3 carbon atoms, such as vinyl and propenyl.

The term (C₂₋₄) alkynyl means a branched or unbranched alkynyl grouphaving at least one triple bond and 2-4 carbon atoms. Preferred alkynylgroups have 2-3 carbon atoms, such as ethynyl and propynyl.

The term (C₁₋₆) acyl means an acyl group derived from a carboxylic acidhaving 1-6 carbon atoms, like formyl, acetyl, propanoyl, butyryl,2-methylpropanoyl, pentanoyl, pivaloyl, and hexanoyl. Likewise, the term(C₁₋₁₅) acyl means an acyl group derived from a carboxylic acid having1-15 carbon atoms. Also included within the definition of (C₁₋₆) acyl or(C₁₋₁₅) acyl are acyl groups derived from dicarboxylic acids, likehemi-maloyl, hemi-succinoyl, hemi-glutaroyl, and so on. Preferred ishemi-succinoyl.

The term halogen means fluorine, chlorine, bromine, or iodine. Whenhalogen is a substituent at an alkyl group, Cl and F are preferred, Fbeing most preferred.

It is understood that the 7α-substituted Δ¹⁴-nandrolone derivatives ofthe invention have the natural configurations 5α, 8β, 9α, 10β, 13β and17β.

The 7α-substituted Δ¹⁴-nandrolone derivatives of this invention have thenatural configurations 5α, 8β, 9α, 10β, 13β and 17β, and may possessalso one or more additional chiral carbon atoms. The compounds maytherefore be obtained as a pure diastereomer, or as a mixture ofdiastereomers. Methods for obtaining the pure diastereomers are wellknown in the art, e.g. crystallization or chromatography.

The compounds of the invention, which are distinguished from theaforementioned known “Segaloff steroid” by the length of the 7αsubstituent, surprisingly are an improvement over said known steroid andhave unexpected advantages for clinical utility. This is exhibited by,inter alia, a surprisingly better oral activity. Preferred compounds ofthe invention further display a much better metabolic stability than theSegaloff steroid.

Preferred compounds of the invention have R₂ selected from the groupconsisting of ethyl, ethenyl, ethynyl, propyl, 1-propenyl, 2-propenyl,1-propynyl, 1,2-propadienyl, and cyclopropyl.

Even more preferred are compounds in which R₁ is oxo, R₃ is hydrogen, R₄is methyl, and the dotted lines indicate a Δ⁴ double bond.

Most preferred are those compounds in which R₂ is C₂, with the highestpreference being ethyl or ethenyl.

The compounds of the invention may be produced by various methods knownin the art of organic chemistry in general, and especially in the art ofthe chemistry of steroids (see, for example: Fried, J. et al, OrganicReactions in Steroid Chemistry, Volumes I and II, Van Nostrand ReinholdCompany, New York, 1972).

Essential is the introduction of a saturated or unsaturated7α-substituent (optionally substituted by halogen) onto the steroidnucleus, and the introduction of a Δ¹⁴ double bond. A convenientstarting material for the preparation of compounds of formula I whereinR₁ is oxo, R₂, R₃ and R₄ have the previously given meaning, R₅ ishydrogen, and the dotted lines indicate a Δ⁴ double bond, is forinstance a gon-4-en-3-one derivative of general formula II, wherein R₃and R₄ have the previously given meaning, and R₆ is oxo,(17α-H,17β-OR₇), or (17α-C≡CH,17β-OR₇), in which R₇ is a hydroxyprotecting group, such as an acyl group, like an acetyl group, a benzoylgroup or a pivaloyl group, an alkoxyalkyl group, like an ethoxyethylgroup or a tetrahydropyranyl (THP) group, or a silyl group, such as atrimethylsilyl group or a tert-butyldimethylsilyl group, whose synthesisis known in literature, or which can be prepared using standard methods.

A possible synthesis route is as follows. A gon-4-en-3-one derivative offormula II can be converted to the the corresponding gona-4,6-dien-3-onederivative by using standard methods, e.g. by conversion to the3-acyloxy- or 3-alkoxygona-3,5-diene derivative followed by reactionwith 2,3,5,6-tetrachloro-1,4-benzoquinone [Solyom, S. et al, Steroids35, 361 (1980)]. Then, the 7α-substituent, or a precursor thereof, isintroduced by conjugate addition (1,6-addition). For this reactionseveral methodologies are known in the art, among others:

1)—Conjugate addition of organocopper reagents [for conjugate additionsof organocopper reagents, see Lipshutz, B. H. et al in Org. Reactions41, p. 135, Wiley, New York, 1992].

2)—Transition metal-mediated (TiCl₄, AlCl₃, ZrCl₄, etc.) reaction of anorganosilicon compound [formal 1,6-addition; see e.g. Nickisch, K. etal, Tetrahedron Lett. 29, 1533 (1988)].

3)—Base-catalyzed conjugate addition of a dialkyl malonate,2,2-dimethyl-1,3-dioxane-4,6-dione, or an alkyl cyanoacetate [see e.g.Cruz, R. et al, Austr. J. Chem. 35, 451 (1982)].

4)—Conjugate addition of a suitable cyanide (MC≡N, M is Li, Na, K, AlR₂,SiR₃ etc.). In general, these methods result in the predominant orexclusive formation of the 7α-isomer.

The 7α-substituted gon-4-en-3-one thus obtained can be aromatized to the3-hydroxygona-1,3,5(10)-triene [Yuan, S.-S. et al, Steroids 39, 279(1982)] which then can be methylated to the 3-methoxy derivative.Conversion to a 3-methoxygona-1,3,5(10)-triene can also be achieveddirectly [Brito, M. et al, Synth. Commun. 26, 623 (1996)]. When R₆ is(17α-H,17β-OR₇), the 17-hydroxy group is deprotected and oxidized toproduce a 3-methoxygona-1,3,5(10)-trien-17-one derivative [for oxidationreactions, see: Hudlicky, M., Oxidations in Organic Chemistry, ACSMonograph 186, Washington, D.C., 1990]. When R₆ is (17α-C≡CH,17β-OR₇),the 17-hydroxy group is again deprotected and the17α-ethynyl-17β-hydroxy derivative is converted to the 17-ketone e.g. byreaction with silver carbonate on celite [Rao, P. N. et al, Steroids 59,621 (1994)] or other methods known in the art. In both cases, conversionto the 17-ketone can also be accomplished prior to aromatization. The3-methoxygona-1,3,5(10)-trien-17-one derivative thus obtained can bebrominated directly, for instance by reaction with copper(II) bromide inbenzene/methanol [Segaloff, A. et al, Steroids 22, 99 (1973)]. The3-methoxygona-1,3,5(10)-trien-17-one derivative can also be converted tothe enol acetate and then treated with bromine [Johnson, W. S. et al, J.Am. Chem. Soc. 79, 2005 (1957)], or to the enol silyl ether followed byreaction with e.g. N-bromosuccinimide [Heathcock, C. H. et al, J. Amer.Chem. Soc. 104, 6081 (1982)]. Dehydrobromination of the 16α-bromoketone,e.g. by reaction with LiBr/Li₂CO₃/DMF [Bull, J. R. et al, J. Chem. Soc.,Perkin Trans. I, 241 (1990)], usually results in a mixture of(14β)-3-methoxygona-1,3,5(10),15-tetraen-17-one and3-methoxygona-1,3,5(10),14-tetraen-7-one derivatives. They can beseparated whereafter the latter is reduced to the corresponding(17β)-3-methoxygona-1,3,5(10),14-tetraen-17-ol derivative by use ofsodium borohydride, lithium aluminium hydride or other reducing agents.

The 7α-substituted 3-methoxygona-1,3,5(10)-trien-17-one derivative canalso be converted to the corresponding cyclic 1,2-ethanediyl acetalwhich is then brominated to afford a(16α)-16-bromo-3-methoxygona-1,3,5(10)-trien-17-one cyclic1,2-ethanediyl acetal derivative. Bromination can be accomplished usingpyridinium tribromide, phenyltrimethylammonium tribromide or otherbrominating agents known in the art [Rasmusson, G. H. et al, Steroids22, 107 (1973)]. The 16α-bromo compound is dehydrobrominated by reactionwith a base, e.g. potassium tert-butoxide in xylene or dimethylsulfoxide, to give the Δ¹⁵ compound [Johnson, supra; Poirier, D. et al,Tetrahedron 47, 7751 (1991)]. Mild hydrolysis of the ethylene ketal, forinstance by treatment with p-toluenesulfonic acid in a mixture ofacetone and water [Johnson, supra], results in a3-methoxygona-1,3,5(10),15-tetraen-17-one derivative which is thenconverted to a 3-methoxygona-1,3,5(10),14,16-pentaen-17-ol acetate byacid-catalyzed reaction with acetic anhydride, isopropenyl acetate orother acetylating agents [Rasmusson, supra; Bull, supra]. The acetate istreated with sodium borohydride or other reducing agents [Rasmusson,supra] to result in the formation of a(17β)-3-methoxygona-1,3,5(10),14-tetraen-17-ol derivative. Optionally, a3-methoxygona-1,3,5(10),15-tetraen-17-one cyclic 1,2-ethanediyl acetalcan be converted by acid-catalyzed isomerization into the correspondingΔ¹⁴ derivative [Ponsold, K. et al, J. Prakt. Chem. 323, 819 (1981)].Removal of the acetal and reduction of 17-oxo produces the(17β)-3-methoxygona-1,3,5(10),14-tetraen-17-ol derivative. A3-methoxygona-1,3,5(10),15-tetraen-17-one can also undergo isomerizationto give a mixture of (14β)-3-methoxygona-1,3,5(10),15-tetraen-17-one and3-methoxygona-1,3,5(10),14-tetraen-17-one derivatives which can beprocessed as described above.

Additional methods to introduce a Δ¹⁵ double bond include: conversion ofa 3-methoxygona-1,3,5(10)-trien-17-one derivative to the enol acetateand reaction with a palladium(II) salt [Takahashi, T. et al, Tetrahedron41, 5747 (1985)], or reaction of the enolate with methyl2-pyridinesulfinate [Dionne, P. et al, Steroids 62, 674 (1997)].

Birch reduction of the 7α-substituted(17β)-3-methoxygona-1,3,5(10),14-tetraen-17-ol derivative thus obtained[Caine, D. in Org. Reactions 23, p. 1, Wiley, New York, 1976] andhydrolysis of the resulting (17β)-3-methoxygona-2,5(10),14-trien-17-olderivative then provides a 7α-substituted(17β)-17-hydroxygona-4,14-dien-3-one derivative of the invention. Incases where the 7α-substituent is constructed from a precursor thereof(i.e. an unsaturated 7α-substituent, a malonic ester fragment, or acyano group, see above), this operation, which can be accomplished usingstandard methods, often must take place simultaneously with theintroduction of the Δ¹⁴ double bond. The precise sequence of reactionsteps needed for construction of the 7α-substituent and for theintroduction of the Δ¹⁴ double bond, including the Birch reduction andthe conversion of the resulting gona-2,5(10)-diene to the 7α-substituted(17β)-17-hydroxygona-4,14-dien-3-one derivative of the invention isdictated by methods common in synthetic strategy (see Example 4 and 5).

Compounds of the invention in which R₁ is (H,H), (H,OR), NOR, with Rbeing hydrogen, (C₁₋₆) alkyl, (C₁₋₆) acyl, are obtained, by usingmethods known in the art, from compounds of formula I in which R₁ isoxo.

Compounds of the invention in which R₅ is (C₁₋₁₅) acyl are obtained, byusing methods known in the art, from compounds of formula I in which R₅is hydrogen.

Compounds of the invention in which the dotted lines indicate a Δ⁵⁽¹⁰⁾double bond are produced from the Δ^(2.5(10)) dienes obtained after theBirch reduction. Alternatively, they can be prepared from Δ⁴ derivativesby isomerization. 5α-Reduced compounds of the invention are producedfrom Δ⁴ derivatives.

The invention will be further explained hereinafter with reference tothe following Examples.

EXAMPLE 1

(7α,17β)-7-Ethyl-17-hydroxyestra-4,14-dien-3-one (a) and (7α,17β)-7-ethyl-17-hydroxyestra-5(10),14-dien-3-one (b)

i)—Chlorotrimethylsilane (19 ml) was added in 5 min. to a suspension of(17α)-17-hydroxy-19-norpregna-4,6-dien-20-yn-3-one [Syntex S.A., GB935116 (1958); 18.0 g] in a mixture of dichloromethane (300 ml) andpyridine (25 ml), cooled to 0° C. After 2 h stirring at 0° C. thereaction mixture was poured into a saturated aqueous solution of sodiumhydrogencarbonate. The product was extracted into dichloromethane; thecombined organic phases were washed with water and brine, dried oversodium sulfate and concentrated under reduced pressure, to afford(17α)-17-[(trimethylsilyl)oxy]-19-norpregna-4,6-dien-20-yn-3-one (22.3g). The product was used in the following step without furtherpurification.

ii)—A mixture of lithium (5.0 g) and dry diethyl ether (200 ml) wascooled to −30° C. Bromoethane (26.9 ml) was added dropwise whereafterthe resulting solution of ethyllithium was transferred to a suspensionof copper(I) iodide (30.6 g) in dry tetrahydrofuran (140 ml), cooled to−30° C. The resulting cuprate solution was stirred for 45 min. at thattemperature and a solution of the product obtained in the previous step(20.0 g) in dry tetrahydrofuran (160 ml) was added dropwise. After 45min. stirring at −25° C., chlorotrimethylsilane (20 ml) was added andstirring was continued for another 30 min. The reaction mixture waspoured into a saturated aqueous solution of ammonium chloride and theproduct was extracted into ethyl acetate. The combined organic phaseswere washed with a saturated aqueous solution of ammonium chloride andbrine, dried over sodium sulfate and concentrated under reducedpressure, to give(7α,17α)-7-ethyl-3,17-bis[(trimethylsilyl)oxy]-19-norpregna-3,5-dien-20-yne(29.5 g). The product was used in the following step without furtherpurification.

iii)—A solution of the product obtained in the previous step (29.5 g) inacetone (400 ml) was treated with hydrochloric acid (2.3 M, 20 ml).After 1.5 h stirring at room temperature, the reaction mixture wasneutralized with a saturated aqueous solution of sodiumhydrogencarbonate. The acetone was removed under reduced pressure andthe product was extracted into ethyl acetate. The combined organicphases were washed with brine, dried over sodium sulfate andconcentrated under reduced pressure, to give(7α,17α)-7-ethyl-17-hydroxy-19-norpregn-4-en-20-yn-3-one (19.5 g). Theproduct was used in the following step without further purification.

iv)—Hydrochloric acid (6 M, 240 ml) was added dropwise to a suspensionof dicalite (240 g) in methanol (1200 ml). After 20 min. stirring atroom temperature the dicalite was collected by fitration and washed withwater until neutral. Then, it was suspended in water (960 ml). Withvigorous stirring, copper(II) nitrate trihydrate (145 g) was added,followed by careful addition of a solution of sodium carbonate (72.2 g)in water (360 ml). After 30 min. stirring, the product was collected byfiltration and washed with water until neutral. The product was dried at80° C. under reduced pressure, to give copper(II) carbonate on dicalite(310 g). A mixture of the product obtained under iii (19.5 g) andcopper(II) carbonate on dicalite (70 g) in toluene (330 ml) was heatedat reflux temperature for 9 h under removal of water by use of aDean-Stark trap. The reaction mixture was filtered, the residuethoroughly washed with ethyl acetate, and the filtrate was concentratedunder reduced pressure. Column chromatography gave(7α)-7-ethylestr-4-ene-3,17-dione (9.14 g).

v)—A solution of the product obtained in the previous step (9.14 g),copper(II) bromide (13.6 g), and lithium bromide (2.64 g) inacetonitrile (285 ml) was stirred at room temperature for 4 h. Thereaction mixture was poured into water and the product extracted intoethyl acetate. The combined organic phases were was washed with asaturated aqueous solution of ammonium chloride and brine, dried oversodium sulfate and concentrated under reduced pressure. Columnchromatography afforded(7α)-7-ethyl-3-hydroxyestra-1,3,5(10)-trien-17-one (6.54 g).

vi)—A mixture of the product obtained in the previous step (6.54 g), drypotassium carbonate (18.6 g), iodomethane (5.6 ml), and drydimethylformamide (22 ml) was stirred at room temperature for 3.5 h. Thereaction mixture was poured into water and the product extracted intoethyl acetate. The combined organic phases were washed with water, asaturated aqueous solution of ammonium chloride and brine, dried oversodium sulfate and concentrated under reduced pressure, to give(7α)-7-ethyl-3-methoxyestra-1,3,5(10)-trien-17-one (6.77 g). The productwas used in the following step without further purification.

vii)—A solution of diisopropylamine (6.15 ml) in dry tetrahydrofuran (70ml) was cooled to −30° C. n-BuLi (1.6 M solution in hexanes, 27.5 ml)was added dropwise and stirring was continued for 30 min. The reactionmixture was cooled to −50° C. and a solution of the product obtained inthe previous step (6.95 g) in dry tetrahydrofuran (100 ml) was addeddropwise. Stirring was continued for 1 h. After cooling to −60° C.,chlorotrimetlhylsilane (11.1 ml) was added. The mixture was stirred for20 min. and then treated with a solution of phenyltrimethylammoniumtribromide (10.0 g) in dry pyridine (31 ml). After 1 h stirring at −60°C., the mixture was poured into water and the product was extracted intoethyl acetate. The combined organic phases were washed with a saturatedaqueous solution of sodium hydrogencarbonate and brine, dried oversodium sulfate and concentrated under reduced pressure. Columnchromatography afforded(7α,16α)-16-bromo-7-ethyl-3-methoxyestra-1,3,5(10)-trien-17-one (8.75g).

viii)—A mixture of the product obtained in the previous step (8.75 g),lithium bromide (12.7 g) and lithium carbonate (10.9 g) in drydimethylformamide (77 ml) was heated under reflux for 3.25 h. Aftercooling, the reaction mixture was poured into water and the product wasextracted into ethyl acetate. The combined organic phases were washedwith water and brine, dried over sodium sulfate and concentrated underreduced pressure. Column chromatography afforded(7α)-7-ethyl-3-methoxyestra-1,3,5(10),14-tetraen-17-one (4.31 g) and(7α,14β)-7-ethyl-3-methoxyestra-1,3,5(10),15-tetraen-17-one (1.0 g).

ix)—A solution of sodium borohydride (0.21 g) and sodium hydroxide (0.44g) in methanol (50 ml) was added dropwise to a solution of(7α)-7-ethyl-3-methoxyestra-1,3,5(10),14-tetraen-17-one (4.31 g) indichloromethane (12 ml) and methanol (20 ml), cooled to 0° C. Thereaction mixture was stirred for 1.5 h, quenched with acetone (4 ml),and then poured into a saturated aqueous solution of ammonium chloride.The product was extracted into ethyl acetate; the combined organicphases were washed with brine, dried over sodium sulfate andconcentrated under reduced pressure, to give(7α,17β)-7-ethyl-3-methoxyestra-1,3,5(10),14-tetraen-17-ol (4.28 g). Theproduct was used in the following step without further purification.

x)—The alcohol obtained in the previous step (1.5 g) in drytetrahydrofuran (24 ml) was added to a refluxing solution of lithium(2.12 g) in liquid ammonia (98 ml). After 4.5 h stirring at −35° C.,2-propanol was added in 30 min. and the ammonia was allowed toevaporate. Water was added and the product was extracted into ethylacetate. The combined organic phases were washed with brine, dried oversodium sulfate and concentrated under reduced pressure, to give(7α,17β)-7-ethyl-3-methoxyestra-2,5(10),14-trien-17-ol (1.65 g). Theproduct was used in the following step without further purification.

xi)—A mixture of silica (5.2 g), a saturated aqueous solution of oxalicacid (0.52 ml) and dichloromethane (14 ml) was stirred at roomtemperature for 10 min. A solution of the product obtained in theprevious step (1.6 g) in dichloromethane (5 ml) was added and stirringwas continued for 1.5 h. Solid sodium hydrogencarbonate was added andstirring was continued for 10 min. The mixture was filtered and thefiltrate was concentrated under reduced pressure. Column chromatographyof the crude product afforded(7α,17D)-7-ethyl-17-hydroxyestra-5(10),14-dien-3-one (1.03 g), ¹H-NMR(CDCl₃)δ5.04 (bs, 1H), 4.03 (t, 1H, J=8.4 Hz), 2.76 (bs, 2H), 0.98 (s,3H), 0.93 (t, 3H, J=6.6 Hz).

xii)—Following a procedure analogous to that described under iii, theproduct obtained in the previous step (0.45 g) was converted to(7α,17β)-7-ethyl-17-hydroxyestra-4,14-dien-3-one (0.24 g), m.p. 102-105°C.

EXAMPLE 2

(7α,17β)-7-Ethenyl-17-hydroxyestra-4,14-dien-3-one

i)—A solution of (17β)-17-(acetyloxy)estra-4,6-dien-3-one [Syntex, DE1143199 (1963); 50.0 g], lithium thiophenoxide (1.0 M solution intetrahydrofuran, 16 ml), copper(I) bromide-dimethyl sulfide complex(3.18 g) and lithium bromide (1.38 g) in dry tetrahydrofuran (167 ml)was cooled to −15° C. Vinylmagnesium chloride (2 M solution intetrahydrofuran, 159 ml) was added dropwise (T≦−15° C.) and stirring wascontinued for 30 min. A saturated aqueous solution of ammonium chloridewas added dropwise and stirring was continued for another 15 min. Thereaction mixture was filtered over dicalite and the product wasextracted into ethyl acetate. The combined organic phases wereconcentrated under reduced pressure and the residue was dissolved intoacetone (1000 ml). Hydrochloric acid (4 M, 100 ml) was added and themixture was stirred for 30 min. at room temperature. A saturated aqueoussolution of sodium hydrogencarbonate was added and the acetone wasremoved under reduced pressure. The product was extracted into ethylacetate; the combined organic phases were washed with brine, dried oversodium sulfate and concentrated under reduced pressure, to give amixture of (7α,17β)-17-(acetyloxy)-7-ethenylestr-4-en-3-one and(7β,17β)-17-(acetyloxy)-7-ethenylestr-4-en-3-one (57.3 g, ratio 85:15).The product was used in the following step without further purification.

ii)—Potassium hydroxide (26.7 g) was added in portions to a solution ofthe product obtained in the previous step (57.3 g) in tetrahydrofuran(833 ml), methanol (738 ml), and water (238 ml). The reaction mixturewas stirred for 45 min. at room temperature and then neutralized withconcentrated hydrochloric acid (20 ml). The tetrahydrofuran and methanolwere partially removed under reduced pressure and the product wasextracted into ethyl acetate. The combined organic phases were washedwith water and brine, dried over sodium sulfate and concentrated underreduced pressure. Column chromatography afforded(7α,17β)-7-ethenyl-17-hydroxyestr-4-en-3-one (36.7 g).

iii)—A mixture of the product obtained in the previous step (66.2 g),trimethyl orthoformate (80 ml), copper(II) bromide (65.2 g), andmethanol (1788 ml) was heated under reflux for 50 min. After cooling,the reaction mixture was filtered. The filtrate was concentrated underreduced pressure and the residu dissolved in ethyl acetate. The ethylacetate solution was washed with a saturated aqueous solution of sodiumhydrogencarbonate and brine, dried over sodium sulfate and concentratedunder reduced pressure. Column chromatography afforded(7α,17,β)-7-ethenyl-3-methoxyestra-1,3,5(10)-trien-17-ol (42.9 g).

iv)—Tetrapropylammonium perruthenate (2.76 g) was added to a solution ofthe product obtained in the previous step (41.1 g) and4-methylmorpholine N-oxide (46.2 g) in acetone (1080 ml). After 1 hstirring at room temperature the reaction mixture was filtered overdicalite and silica. The filtrate was concentrated under reducedpressure. Column chromatography afforded(7α)-7-ethenyl-3-methoxyestra-1,3,5(10)-trien-17-one (38.1 g).

v)—p-Toluenesulfonic acid (3.21 g) was added to a solution of theproduct obtained in the previous step (36.05 g) in a mixture of ethyleneglycol (108 ml) and triethyl orthoformate (188 ml). The reaction mixturewas stirred at room temperature for 2 h. Water (1800 ml) was added andstirring was continued for 1 h. The product was extracted into ethylacetate; the combined organic phases were washed with a saturatedaqueous solution of sodium hydrogencarbonate and brine, dried oversodium sulfate, and concentrated under reduced pressure, to give(7α)-7-ethenyl-3-methoxyestra-1,3,5(10)-trien-17-one cyclic1,2-ethanediyl acetal (41.37 g). The product was used in the followingstep without further purification.

vi)—Phenyltrimethylammonium tribromide (22.60 g) was added in portionsto a solution of the product obtained in the previous step (21.37 g) indry tetrahydrofuran (114 ml). The reaction mixture was stirred for 40min., and then treated with additional portions ofphenyltrimethylammonium tribromide until the reaction was complete.After 30 min. stirring the mixture was poured into an aqueous solutionof sodium thiosulfate (10%) and the product was extracted into ethylacetate. The combined organic phases were washed with a saturatedaqueous solution of sodium hydrogencarbonate and brine, dried oversodium sulfate and concentrated under reduced pressure, to give(7α,16α)-16-bromo-7-ethenyl-3-methoxyestra-1,3,5(10)-trien-17-one cyclic1,2-ethanediyl acetal (34.91 g). The product was used in the followingstep without further purification.

vii)—A solution of the product obtained in the previous step (34.91 g)in dry dimethyl sulfoxide (178 ml) was treated with potassiumtert-butoxide (13.5 g) and the reaction mixture was stirred at 40° C.for 3 h. Additional amounts of potassium tert-butoxide (13.5 g) wereadded after 30 min. and 1 h, respectively. The mixture was poured into asaturated aqueous solution of ammonium chloride and the product wasextracted into ethyl acetate. The combined organic phases were washedwith a saturated aqueous solution of ammonium chloride and brine, driedover sodium sulfate and concentrated under reduced pressure. Columnchromatography provided(7α)-7-ethenyl-3-methoxyestra-1,3,5(10),15-tetraen-17-one cyclic1,2-ethanediyl acetal (17.54 g).

viii)—A solution of the product obtained in the previous step (31.47 g)in a mixture of acetone (507 ml) and water (43 ml) was treated withp-toluenesulfonic acid (1.48 g) and the reaction mixture was stirred atroom temperature for 2 h. The reaction mixture was poured into asaturated aqueous solution of sodium hydrogencarbonate and the productwas extracted into ethyl acetate. The combined organic phases werewashed with brine, dried over sodium sulfate and concentrated underreduced pressure. Column chromatography afforded(7α)-7-ethenyl-3-methoxyestra-1,3,5(10),15-tetraen-17-one (23.92 g).

ix)—A solution of the product obtained in the previous step (23.9 g) indry toluene (970 ml) was treated with p-toluenesulfonic acid (13.5 g)and heated under reflux for 15 min. After cooling, the reaction mixturewas poured into a saturated aqueous solution of sodium hydrogencarbonateand the product was extracted into ethyl acetate. The combined organicphases were washed with brine, dried over sodium sulfate andconcentrated under reduced pressure. Column chromatography afforded(7α)-7-ethenyl-3-methoxyestra-1,3,5(10),14-tetraen-17-one (14.9 g) and(7α,14β)-7-ethenyl-3-methoxyestra-1,3,5(10), 15-tetraen-17-one (7.32 g).

x)—Sodium borohydride (1.47 g) was added to a solution of(7α)-7-ethenyl-3-methoxyestra-1,3,5(10),14-tetraen-17-one (1.50 g)obtained in the previous step in a mixture of tetrahydrofuran (27.8 ml),ethanol (27.8 ml) and water (4.55 ml). The reaction mixture was stirredfor 50 min. and then poured into water. The product was extracted intoethyl acetate. The combined organic phases were washed with water andbrine, dried over sodium sulfate and concentrated, to afford(7α,17β)-7-ethenyl-3-methoxyestra-1,3,5(10),14-tetraen-17-ol (1.47 g).The product was used in the following step without further purification.

xi)—A solution of the product obtained in the previous step (1.47 g) indry tetrahydrofuran (26 ml) was added to refluxing liquid ammonia (105ml). Lithium granulate (0.95 g) was added and the reaction mixture wasstirred for 1.25 h. Dry tert-butanol (9.2 ml) was added and the reactionmixture was stirred for an additional 30 min. Solid ammonium chloridewas added and the ammonia was allowed to evaporate. Water was added andthe product was extracted into ethyl acetate. The combined organicphases were washed with a saturated aqueous solution of ammoniumchloride and brine, dried over sodium sulfate, and concentrated underreduced pressure, to afford(7α,17β)-7-ethenyl-3-methoxyestra-2,5(10),14-trien-17-ol (1.48 g). Theproduct was used in the following step without further purification.

xii)—Following a procedure analogous to that described under iii ofExample 1, the product obtained in the previous step (1.48 g) washydrolyzed to afford, after column chromatography and crystallization,(7α,17β)-7-ethenyl-17-hydroxyestra-4,14-dien-3-one (0.419 g), m.p.129-136° C.

EXAMPLE 3

(7α,17β)-17-Hydroxy-7-propylestra-4,14-dien-3-one

The title compound was prepared in a manner analogous to that describedunder Example 1. ¹H-NMR (CDCl₃) δ5.86 (bs, 1H), 5.08 (m, 1H), 4.00 (q,1H, J=7.2 Hz), 1.00 (s, 3H), 0.89 (t, 3H, J=6.2 Hz).

EXAMPLE 4

(7α,17β)-17-Hydroxy-7-(2-propenyl)estra-4,14-dien-3-one

i)—A mixture of lithium granulate (containing 0.5% sodium; 5.60 g) indry diethyl ether (250 ml) was cooled to −30° C.1-Bromo-3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]propane (101.2 g) wasadded in 45 min. while maintaining the temperature below 0° C. Afteraddition of the bromide, the reaction mixture was stirred for anadditional 45 min. at 20° C. In a second flask, a suspension ofcopper(I) iodide (38.1 g) in dry tetrahydrofuran (200 ml) was cooled to−30° C. The solution of organolithium compound was added in 5 min.(−20≦T≦−10° C.), and stirring was continued for an additional 5 min.Then, a solution of(17α)-17-[(trimethylsilyl)oxy]-19-norpregna-4,6-dien-20-yn-3-one(Example 1, step i; 51.6 g) in dry tetrahydrofuran (200 ml) was added in5 min. and the reaction mixture was stirred at −20° C. for 1 h. Themixture was poured into a saturated aqueous solution of ammoniumchloride and concentrated ammonia (9:1) and the product was extractedinto ethyl acetate. The combined organic phases were washed with asaturated aqueous solution of sodium hydrogencarbonate and brine, driedover sodium sulfate and concentrated. The residue was dissolved inacetone (500 ml). Hydrochloric acid (6 M, 25 ml) was added and thereaction mixture was stirred at room temperature for 2 h. A saturatedaqueous solution of sodium hydrogencarbonate was added and the acetonewas removed. The product was extracted into ethyl acetate; the combinedorganic phases were washed with brine, dried over sodium sulfate andconcentrated. Column chromatography afforded(7α,17β)-17-hydroxy-7-(3-hydroxypropyl)-19-norpregn-4-en-20-yn-3-one(39.4 g).

ii)—A solution of the product obtained in the previous step (38.4 g) ina mixture of pyridine (215 ml) and acetic anhydride (108 ml) was stirredat room temperature for 1 h. The reaction mixture was poured into water(1000 ml) and stirring was continued for another 1 h. The product wasextracted into ethyl acetate; the combined organic phases were washedwith water and brine, dried over sodium sulfate and concentrated underreduced pressure, to give(7α,17α)-17-hydroxy-7-[3-(acetyloxy)propyl]-19-norpregn-4-en-20-yn-3-one(40.5 g). The product was used in the following step without furtherpurification.

iii)—Following a procedure analogous to that described under iv ofExample 1, the product obtained in the previous step (40.5 g) wasconverted to (7α)-7-[3-(acetyloxy)propyl]estr-4-ene-3,17-dione (39.0 g).

iv)—Following a procedure analogous to that described under v of Example1, the product obtained in the previous step (39.0 g) was converted to(7α)-7-[3-(acetyloxy)propyl]-3-hydroxyestra-1,3,5(10)-trien-17-one (36.8g).

v)—Following a procedure analogous to that described under vi of Example1, the product obtained in the previous step (36.8 g) was converted to(7α)-7-[3-(acetyloxy)propyl]-3-methoxyestra-1,3,5(10)-trien-17-one (19.3g).

vi)—Following a procedure analogous to that described under v of Example2, the product obtained in the previous step (19.3 g) was converted(7α)-7-[3-(acetyloxy)propyl]-3-methoxyestra-1,3,5(10)-trien-17-onecyclic 1,2-ethanediyl acetal (21.8 g).

vii)—A solution of the product obtained in the previous step (21.8 g) indry tetrahydrofuran (224 ml) was added dropwise to a suspension oflithium aluminium hydride (6.58 g) in dry tetrahydrofuran (448 ml),cooled to 0° C. After 1 h stirring, the reaction was quenched byaddition of a saturated aqueous solution of sodium sulfate. Ethylacetate was added, and the mixture was filtered over dicalite. Thefiltrate was concentrated under reduced pressure to give(7α)-7-(3-hydroxypropyl)-3-methoxyestra-1,3,5(10)-trien-17-one cyclic1,2-ethanediyl acetal (18.9 g). The product was used in the followingstep without further purification.

viii)—A solution of the product obtained in the previous step (18.7 g)in dry dimethoxyethane (80 ml) was added dropwise to a solution ofpyridinium tribromide (35.9 g) in a mixture of dry dimethoxyethane (80ml) and ethylene glycol (28 ml) while avoiding the temperature to riseabove room temperature. After 1 h stirring the mixture was poured into asolution of sodium thiosulfate (27.1 g) in water (159 ml) and theproduct was extracted into ethyl acetate. The combined organic phaseswere washed with water, a saturated aqueous solution of sodiumhydrogencarbonate and brine, dried over sodium sulfate and concentratedunder reduced pressure, to give(7α,16α)-16-bromo-7-(3-hydroxypropyl)-3-methoxyestra-1,3,5(10)-trien-17-onecyclic 1,2-ethanediyl acetal (24.3 g). The product was used in thefollowing step without further purification.

ix)—Following a procedure analogous to that described under vii ofExample 2, the product obtained in the previous step (24.3 g) wasconverted to(7α)-7-(3-hydroxypropyl)-3-methoxyestra-1,3,5(10),15-tetraen-17-onecyclic 1,2-ethanediyl acetal (13.1 g).

x)—Following a procedure analogous to that described under viii ofExample 2, the product obtained in the previous step (5.46 g) wasconverted to(7α)-7-(3-hydroxypropyl)-3-methoxyestra-1,3,5(10),15-tetraen-17-one(5.01 g).

xi)—A solution of the ketone obtained in the previous step (3.19 g) andpyridinium p-toluenesulfonate (0.94 g) in isopropenyl acetate (94 ml)was heated under reflux for 1.5 h. After cooling, the reaction mixturewas poured into a saturated aqueous solution of sodiumhydrogencarbonate. The product was extracted into diethyl ether; thecombined organic phases were washed with brine, dried over sodiumsulfate, and concentrated under reduced pressure, to give(7α)-7-[3-(acetyloxy)propyl]-3-methoxyestra-1,3,5(10),14,16-pentaen-17-ol acetate (3.69 g). The product was used in thefollowing step without further purification.

xii)—Following a procedure analogous to that described under x ofExample 2, the product obtained in the previous step (3.69 g) wasconverted to (7α,17β)-7-[3-(acetyloxy)propyl]-3-methoxyestra-1,3,5(10),14-tetraen-17-ol (2.49 g).

xiii)—A solution of the alcohol obtained in the previous step (2.49 g)and imidazole (2.20 g) in dry dichloromethane (13 ml) was treated withtert-butyldimethylsilyl chloride (1.46 g). After 2 h stirring at roomtemperature the reaction mixture was poured into a saturated aqueoussolution of sodium hydrogencarbonate. The product was extracted intodiethyl ether; the combined organic phases were washed with water andbrine, dried over sodium sulfate and concentrated under reducedpressure, to give(7α,17β)-7-[3-(acetyloxy)propyl]-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-3-methoxyestra-1,3,5(10),14-tetraene (3.43 g). The product was used in the next step withoutfurther purification.

xiv)—Following a procedure analogous to that described under vii, theproduct obtained in the previous step (3.43 g) was converted to(7α,17β)-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-7-(3-hydroxypropyl)-3-methoxyestra-1,3,5(10),14-tetraene(1.96 g).

xv)—Iodine (0.292 g) was added to a solution of triphenylphosphine (0.32g) and imidazole (0.082 g) in dry dichloromethane (7.5 ml). Aftercomplete reaction of the iodine, a solution of the product obtained inthe previous step (0.25 g) in dry dichloromethane (3 ml) was added andthe mixture stirred for 30 min. at room temperature. Then it was pouredinto a saturated aqueous solution of sodium thiosulfate and the productextracted into diethyl ether. The combined organic phases were washedwith water, a saturated aqueous solution of sodium hydrogencarbonate andbrine, dried over sodium sulfate and concentrated under reducedpressure. Column chromatography afforded(7α,17β)-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-7-(3-iodopropyl)-3-methoxyestra-1,3,5(10),14-tetraene(0.29 g).

xvi)—A solution of the iodide obtained in the previous step (0.17 g) indimethylsulfoxide (5 ml) was treated with potassium tert-butoxide (1.62g) and the reaction mixture was stirred at room temperature for 1 h. Themixture was poured into a saturated aqueous solution of ammoniumchloride and the product was extracted into diethyl ether. The combinedorganic phases were washed with water and brine, dried over sodiumsulfate and concentrated under reduced pressure. Column chromatographyafforded (7α,17β)-3-methoxy-7-(2-propenyl)estra-1,3,5(10),14-tetraen-17-ol (0.075 g).

xvii)—The alcohol obtained in the previous step (0.15 g) in drytetrahydrofuran (5 ml) was added to a refluxing solution of lithium(0.42 g) in liquid ammonia (30 ml). After 1 h stirring at −40° C.,tert-butanol (4 ml) was added and stirring was continued for 30 min.Ethanol (8 ml) was added and the ammonia was allowed to evaporate. Themixture was poured into water and the product was extracted into ethylacetate. The combined organic phases were washed with brine, dried oversodium sulfate and concentrated under reduced pressure, to give amixture of (7α,17β)-3-methoxy-7-(2-propenyl)estra-2,5(10),14-trien-17-oland (7α,17β)-3-methoxy-7-propylestra-2,5(10),14-trien-17-ol (0.144 g,ratio 2:3).

xviii)—Following a procedure analogous to that described under iii ofExample 1, the product obtained in the previous step (0.144 g) washydrolyzed to obtain, after column chromatography and preparative HPLC(reversed phase), (7α,17β)-17-hydroxy-7-(2-propenyl)estra-4,14-dien-3-one (0.018 g), [α]_(D) ²⁰=+6.2° (c=0.89, dioxane).

EXAMPLE 5

(7α,17β)-7-Butyl-17-hydroxyestra-4,14-dien-3-one (a) and(7α,17β)-7-(3-butenyl)-17-hydroxyestra-4,14-dien-3-one (b)

i)—Following a procedure analogous to that described under iv of Example2,(7α,17β)-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-7-(3-hydroxypropyl)-3-methoxyestra-1,3,5(10),14-tetraene(Example4, step xiv; 0.40 g) was converted to3-[(7α,17β)-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-3-methoxyestra-1,3,5(10),14-tetraen-7-yl]propanal(0.40 g).

ii)—A mixture of methyltriphenylphosphonium bromide (0.94 g), potassiumtert-butoxide (0.26 g) and dry toluene (10 ml) was heated under refluxfor 1 h. A solution of the aldehyde obtained in the previous step (0.40g) in dry toluene (5 ml) was added and heating was continued for another1 h. After cooling, the reaction mixture was poured into a saturatedaqueous solution of ammonium chloride. The product was extracted intoethyl acetate; the combined organic phases were washed with brine, driedover sodium sulfate and concentrated under reduced pressure. Columnchromatography afforded(7α,17β)-7-(3-butenyl)-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-3-methoxyestra-1,3,5(10),14-tetraene(0.40 g).

iii)—Following a procedure analogous to that described under iii ofExample 1, the product obtained in the previous step (0.40 g) wasconverted to(7α,17β)-7-(3-butenyl)-3-methoxyestra-1,3,5(10),14-tetraen-17-ol (0.39g).

iv)—Following a procedure analogous to that described under xvii ofExample 4, the product described in the previous step (0.39 g) wasconverted to a mixture of(7α,17β)-7-butyl-3-methoxyestra-2,5(10),14-trien-17-ol and(7α,17β)-7-(3-butenyl)-3-methoxyestra-2,5(10),14-trien-17-ol (0.37 g,ratio 3:1).

v)—Following a procedure analogous to that described under iii ofExample 1, the product obtained in the previous step (0.37 g) washydrolyzed to give, after column chromatography and preparative HPLC(reversed phase), (7α,17β)-7-butyl-17-hydroxyestra-4,14-dien-3-one(0.043 g), [α]_(D) ²⁰=+7.6° (c=0.185, dioxane), and(7α,17β)-7-(3-butenyl) -17-hydroxyestra-4,14-dien-3-one (0.077 g),[α]_(D) ²⁰=+4.4° (c=0.475, dioxane).

EXAMPLE 6

(7α,17β)-7.13-Diethyl-17-hydroxygona-4,14-dien-3-one

i)—Pyridinium-toluenesulfonate (5.0 g) was added to a solution of13-ethylgon-4-ene-3,17-dione [Hoffmann-La Roche and Co.; AG, DE 1806410(1967); 100.0 g] in a mixture of ethanol (600 ml), dioxane (800 ml) andtriethyl orthoformate (199 ml). After 4.5 h stirring at room temperaturepyridine (100 ml) was added and the reaction mixture was poured into asaturated aqueous solution of sodium hydrogencarbonate. The product wasextracted into ethyl acetate; the combined organic phases were washedwith water and brine, dried over magnesium sulfate and concentratedunder reduced pressure, to give 3-ethoxy-13-ethylgona-3,5-dien-17-one(146.3 g). The product was used in the following step without furtherpurification.

ii)—Following a procedure analogous to that described under vii ofExample 4, the product obtained in the previous step (73.2 g) wasconverted to (17β)-3-ethoxy-13-ethylgona-3,5-dien-17-ol (58.0 g).

iii)—A solution of the product obtained in the previous step (58.0 g) intetrahydrofuran (215 ml), containing pyridine (2.5 ml), was added to asuspension of tetrachloro-1,4-benzoquinone (49.6 g) in a mixture ofethanol (525 ml) and water (60 ml). The reaction mixture was stirred atroom temperature for 4.5 h and then treated with a solution of sodiumhydrogensulfite (26.7 g) in water (385 ml). After 30 min. stirring, asaturated aqueous solution of sodium sulfite was added and the productwas extracted into ethyl acetate. The combined organic phases werewashed with a saturated aqueous solution of sodium sulfite, water andbrine, dried over magnesium sulfate and concentrated under reducedpressure, to give a brown oil (81.0 g). The reaction was repeated with57.0 g of 3,5-diene to give 79.0 g of crude product. Columnchromatography of the combined crude products afforded(17β)-13-ethyl-17-hydroxygona-4,6-dien-3-one (56.3 g).

iv)—Following a procedure analogous to that described under xiii ofExample 4, the product obtained in the previous step (56.3 g) wasconverted to (17β)-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-13-ethylgona-4,6-dien-3-one (65.6 g).

v)—Following a procedure analogous to that described under i of Example2, using ethyl magnesium bromide, the product obtained in the previousstep (25.0 g) was converted to(7α,17β)-7,13-diethyl-17-hydroxygon-4-en-3-one (8.13 g).

vi)—Following a procedure analogous to that described under iii ofExample 2, the product obtained in the previous step (8.24 g) wasconverted to (7α,17β)-7,13-diethyl-3-methoxygona-1,3,5(10)-trien-17-ol(6.28 g).

vii)—Following a procedure analogous to that described under iv ofExample 2, the product obtained in the previous step (5.72 g) wasconverted to (7α)-7,13-diethyl-3-methoxygona-1,3,5(10)-trien-17-one(5.61 g).

viii)—Following a procedure analogous to that described under v ofExample 2, the product obtained in the previous step (5.61 g) wasconverted to (7α)-7,13-diethyl-3-methoxygona-1,3,5(10)-trien-17-onecyclic 1,2-ethanediyl acetal (6.99 g).

ix)—Following a procedure analogous to that described under vi ofExample 2, the product obtained in the previous step (6.27 g) wasconverted to(7α,16β)-16-bromo-7,13-diethyl-3-methoxygona-1,3,5(10)-trien-17-onecyclic 1,2-ethanediyl acetal (8.47 g).

x)—Following a procedure analogous to that described under vii ofExample 2, the product obtained in the previous step (8.47 g) wasconverted to (7α)-7,13-diethyl-3-methoxygona-1,3,5(10),15-tetraen-17-onecyclic 1,2-ethanediyl acetal (5.21 g).

xi)—A solution of the product obtained in the previous step (4.61 g) indry toluene (120 ml) was treated with pyridinium p-toluenesulfonate(3.18 g) and heated under reflux for 1 h. After cooling, the reactionmixture was poured into a saturated aqueous solution of sodiumhydrogencarbonate and the product was extracted into ethyl acetate. Thecombined organic phases were washed with water and brine, dried overmagnesium sulfate and concentrated under reduced pressure, to give(7α)-7,13-diethyl-3-methoxygona-1,3,5(10),14-tetraen-17-one cyclic1,2-ethanediyl acetal (4.44 g). The product was used in the followingstep without further purification.

xii)—A solution of the product obtained in the previous step (4.44 g) indry toluene (120 ml) was treated with p-toluenesulfonic acid (2.29 g)and heated under reflux for 45 min. After cooling, the reaction mixturewas poured into a saturated aqueous solution of sodium hydrogencarbonateand the product was extracted into ethyl acetate. The combined organicphases were washed with water and brine, dried over magnesium sulfateand concentrated under reduced pressure, to give(7α)-7,13-diethyl-3-methoxygona-1,3,5(10),14-tetraen-17-one (3.89 g).The product was used in the following step without further purification.

xiii)—Following a procedure analogous to that described under vii ofExample 4, the product described in the previous step (3.89 g) wasconverted to(7α,17β)-7,13-diethyl-3-methoxygona-1,3,5(10),14-tetraen-17-ol (2.79 g).

xiv)—Following a procedure analogous to that described under xvii ofExample 4, the product obtained in the previous step (2.0 g) wasconverted to (7α,17β)-7,13-diethyl-3-methoxygona-2,5(10),14-trien-17-ol(1.77 g).

xv)—Following a procedure analogous to that described under iii ofExample 1, the product described in the previous step (1.77 g) wasconverted to (7α,17β)-7,13-diethyl-17-hydroxygona-4,14-dien-3-one (0.36g), m.p. 181.5-183.5° C.

EXAMPLE 7

(7α,17β)-7-Ethenyl-13-ethyl-17-hydroxygona-4,14-dien-3-one

i)—Following a procedure analogous to that described under i of Example2, (17β)-17-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-13-ethylgona-4,6-dien-3-one (Example 6, step iv; 25.0g) was converted to (7α,17β)-7-ethenyl-13-ethyl-17-hydroxygon-4-en-3-one(8.20 g).

ii)—Following a procedure analogous to that described under iii ofExample 2, the product obtained in the previous step (7.76 g) wasconverted to(7α,17β)-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10)-trien-17-ol (5.16g).

iii)—Following a procedure analogous to that described under iv ofExample 2, the product obtained in the previous step (5.43 g) wasconverted to(7α)-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10)-trien-17-one (5.08 g).

iv)—Following a procedure analogous to that described under v of Example2, the product obtained in the previous step (4.92 g) was converted to(7α)-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10)-trien-17-one cyclic1,2-ethanediyl acetal (5.42 g).

v)—Following a procedure analogous to that described under vi of Example2, the product obtained in the previous step (5.08 g) was converted to(7α,16α)-16-bromo-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10)-trien-17-onecyclic 1,2-ethanediyl acetal (7.41 g).

vi)—Following a procedure analogous to that described under vii ofExample 2, the product obtained in the previous step (7.41 g) wasconverted to(7α)-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10),15-tetraen-17-one cyclic1,2-ethanediyl acetal (3.87 g).

vii)—Following a procedure analogous to that described under xi ofExample 6, the product obtained in the previous step (3.42 g) wasconverted to(7α)-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10),14-tetraen-17-one cyclic1,2-ethanediyl acetal (3.30 g).

viii)—Following a procedure analogous to that described under xii ofExample 6, the product obtained in the previous step (3.30 g) wasconverted to(7α)-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10),14-tetraen-17-one (3.0g).

ix)—Following a procedure analogous to that described under vii ofExample 4, the product obtained in the previous step (3.00 g) wasconverted to(7α,17β)-7-ethenyl-13-ethyl-3-methoxygona-1,3,5(10),14-tetraen-17-ol(1.70 g).

x)—Following a procedure analogous to that described under xvii ofExample 4, the product obtained in the previous step (1.49 g) wasconverted to(7α,17β)-7-ethenyl-13-ethyl-3-methoxygona-2,5(10),14-trien-17-ol (1.60g).

xi)—Following a procedure analogous to that described under iii ofExample 1, the product obtained in the previous step (1.60 g) wasconverted to (7α,17β)-7-ethenyl-13-ethyl-17-hydroxygona-4,14-dien-3-one(0.47 g), m.p. 141-145° C.

EXAMPLE 8

(3β,7α,17β)-7-Ethylestra-4,14-diene-3,17-diol

Following a procedure analogous to that described under vii of Example4, the title compound was prepared from(7α,17β)-7-ethyl-17-hydroxyestra-4,14-dien-3-one (Example 1a). ¹H-NMR(CDCl₃) δ5.39 (m, 1H), 5.01 (m, 1H), 4.21 (m, 1H), 3.96 (m, 1H), 0.98(s, 3H), 0.87 (t, 3H, J=7.6 Hz).

EXAMPLE 9

(5α,7α,17β)-7-Ethyl-17-hydroxyestr-14-en-3-one

A solution of (7α,17β)-7-ethyl-17-hydroxyestra-4,14-dien-3-one (Example1a; 0.67 g) in dry tetrahydrofuran (13 ml) was added to a refluxingsolution of lithium (0.31 g) in liquid ammonia (44 ml). After 30 min.stirring at −40° C., solid ammonium chloride was added and the ammoniawas allowed to evaporate. Water was added and the product was extractedinto ethyl acetate. The combined organic phases were washed with asaturated aqueous solution of ammonium chloride and brine, dried oversodium sulfate and concentrated under reduced pressure. Columnchromatography afforded (5α,7α,17β)-7-ethyl-17-hydroxyestr-14-en-3-one(0.21 g), ¹H-NMR (CDCl₃) δ5.02 (s, 1H), 3.98 (t, 1H, J=8.4 Hz), 0.99 (s,3H), 0.89 (t, 3H, J=7.5 Hz).

EXAMPLE 10

The LH Suppression Assay: Determination of Oral Activity

The in vivo potency (po) of several androgens of the invention wasdetermined in a mature male castrated rat model, in comparison wihSegaloff compound. In this model serum LH is high (50× fold higher thanwith intact rats, due to the absence of the negative feedback oftesticular testosterone). These rats are po treated for 4 days dailywith a given compound of the invention in a suspension fluid of arachisoil. Before dosing and 3 hours after the last oral dose blood iscollected via tail vene and in the serum LH is determined. Potency (po)of the androgens (ED₅₀) are expressed as the amount (mg/kg) of androgenwhich suppresses serum LH for 50% (±10%).

The rat LH Time-Resolved Immuno Fluorometric Assay (TR-IFMA) has beendeveloped in house using home made reagents, a monoclonal catchingantibody directed against the β-subunit of human chorion gonadotrophin(hCG, which cross react with rat β-subunit) and a biotin labelleddetecting antibody (rabbit polyclonal antibody directed against thealfa-subunit of recombinant rat LH). Recombinant rat LH was preparedaccording to the methods described by Hakola et al (1997). In thistwo-site-IFMA, only intact rat LH is determined by a final incubationwith streptavidin-europium. The detection in the IFMA is based onfluorescence of the lanthanide europium during a relative long exitationperiod. The concentration range of rat LH standard is 0.001-10 ng/ml,for optimal accuracy measurements of serum LH serum samples were diluted8-times with assay buffer [Hakola, K., Boogaart, P. V., Mulders, J., deLeeuw, R., Schoonen, W., Heyst, J. V., Swolfs, A., Casteren, J. V.,Huhtaniemi, I., and Kloosterboer, H. J., Recombinant rat luteinizinghormone; production by Chinese hamster ovary cells, purification andfunctional characterization, Molecular & Cellular Endocrinology 128, 47(1997)].

Results

TABLE ED₅₀ (po) of androgens of the invention required to suppress serumLH for 50% (±10%). Example ED₅₀ (mg/kg) 1a 0.2 2 0.5 Segaloff 5compound* *(7α,17β)-7-Methyl-17-hydroxyestra-4,14-dien-3-one

EXAMPLE 11

Determination of t_(1′2) of Androgens of the Invention after Incubationwith Human Hepatocytes

The half-life of a compound as a result of contact with humanhepatocytes holds as a reliable indication of metabolic stability. As itis well known that the absorption of this class of steroids is high,this assay provides an in vitro model for oral activity in humans. Itwill be understood that a shorter half-life indicates that a compoundwill be metabolized more rapidly or, vice versa, the longer thehalf-life, the better the compound may exert its effect upon the humanbody when administered orally.

Hepatocytes collected from healthy young (25-45 year) male organ donorswere cryo preserved in liquid nitrogen and kept there until use. Theywere thawed at 37° C. in a waterbath, placed immediately on ice, washedtwice in one volume of cold (4° C.) incubation medium [William's mediumE (without phenol red) with Glutamax I®, gentamicin 50 μg/ml, insulin 1μM, hydrocortisone hemisuccinate 10 μM, fetal calf serum 0% (v/v)],counted and the viability checked by Trypan blue exclusion. Cells wereincubated as suspensions in 12-wells (non-coated) plates at a nominaldensity of 0.5×10⁶ cells/well in 1.5 ml medium at 37° C. with anair/O₂/CO₂ mixture (55/40/5). The plates were set on an orbital shakerat approximately 10 rpm.

The hepatocytes were incubated with 10 nM final concentration of thecompound to be tested. The incubations were stopped after 0.5, 1 and 3 hby pipetting the whole incubation mixture into a glass tube and addingone volume of acetone on ice. The acetone was dried under a nitrogenflow at room temperature, the volume adjusted to 1.5 ml and the tubeswere centrifuged at 4° C. at 10.000×g for 30 min. The de-proteinizedsupernatants were collected for LC-MS/MS analysis.

Results

TABLE t_(1/2) of androgens of the invention after incubation with humanhepatocytes. Example t_(1/2) (min) 1a 157 2 40 Segaloff 60 compound**(7α, 17β)-7-Methyl-17-hydroxyestra-4,14-dien-3-one

What is claimed is:
 1. A kit for male contraception comprising aprogestagen and an androgen, wherein the androgen is a pharmaceuticalformulation comprising a compound of formula I:

wherein R₁ is O,(H,H), (H,OR), or NOR, with R being hydrogen. (C₁₋₆)alkyl or C₁₋₆) acyl; R₂ is (C₂₋₄) alkyl, (C₂₋₄) alkenyl (C₂₋₄) alkynyl,cyclopropyl, or cyclopropenyl; R₃ is hydrogen, (C₁₋₂) alkyl, or ethenyl;R₄ (C₁₋₂) alkyl; and, R₅ is hydrogen or (C₁₋₁₅) acyl.
 2. The kitaccording to claim 1, wherein R₂ is selected from the group consistingof ethyl, ethenyl, ethnyl, propyl, 1-propenyl, 2-propenyl, 1-propynyl,1,2-propadienyl and cyclpropyl.
 3. The kit according to claim 2, whereR2 is selected from the group consisting of aethyl, a ethenyl and aethynyl.